The present invention relates to a control apparatus for controlling a multi-jointed arm mechanism which is composed of a plurality of arm elements associated with one another and joints for coupling them.
A multi-jointed arm mechanism which consists of a plurality of arm elements associated with one another and joints for coupling them is, for example, the multi-articulated arm mechanism of a robot as disclosed in U.S. Pat. No. 4,221,997. In such multi-jointed arm mechanism, it is necessary to detect the movement magnitudes of the respective arm elements of this multi-jointed arm mechanism by means of a sensor and to adjust the outputs of the respective arm elements on the basis of the outputs of the sensor. Especially in the multi-jointed arm mechanism, the arm elements are associated with one another, so that the outputs of the respective arm elements need to be adjusted while holding cooperative relations with the other arm elements associated with one another. In order to realize such cooperative control, there has heretofore been adopted a concentrated type control apparatus comprising a single calculator which integrates and controls the plurality of arm elements. The concentrated type control apparatus applies the signals from the sensor to the single calculator, which computes on the basis of the input signals the request outputs of all of the plurality of arm elements constituting the multi-jointed arm mechanism and associated with one another, and it supplies the respective arm elements with the computed values as control signals and controls the respective arm elements so as to agree with the target values thereof. Thus, since the respective arm elements are operated and controlled on the basis of the control signals from the single calculator, problems stated below are involved. That is, in computing the control signals of the large number of arm elements collectively with the single calculator, a matrix operation on a large scale is required. A considerable period of time is needed for executing the matrix operation, so that the control apparatus and also the whole multi-jointed arm mechanism come to have unfavorable response rates. The degradations of the response rates form a hindrance to the high operating speed of the the multi-jointed arm mechanism.